I think they do often get it wrong, but they sell a good product from a the world's most recognised luxury brand. Banksy could stencil a turd and the demand would be huge.
Labelling a disaster is fair enough when the new release of an ExpII is the same as the old one, the Oyster bracelet on the GMT, they've done that before, and an Explorer in 36mm - it'd be revolutionary had they not already done that before too. Rolex seem to be brand that looks to the future not the past, yet here they are going through the back catalogue on new release day.
Of course all models will be an instant sell out in today's market, but so would a Sub on an Oysterflex, a Coke GMT, a ceramic bezel ExpII and white dial Explorer.
With social media, internet blogs, forums etc. it's never been easier for brands to listen to customers to find out what they really want, yet nobody asked for a two tone Explorer. Ever.
Still demand for the Submariner 41mm will be as strong as ever, because occasionally they get it bang on.